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Journal Cover Reactive and Functional Polymers
  [SJR: 0.879]   [H-I: 62]   [5 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1381-5148
   Published by Elsevier Homepage  [2969 journals]
  • Sequential separation method for the determination of uranium and thorium
           in soil using diamyl amylphosphonate and Aliquat®336 impregnated
           polymer resins
    • Abstract: Publication date: September 2016
      Source:Reactive and Functional Polymers, Volume 106
      Author(s): Young Gun Ko, Jong-Myoung Lim, Hoon Lee, Kun Ho Chung, Mun Ja Kang
      The accurate and rapid determination of radionuclides in soil is very important to monitor the radioactivity of radionuclides for reduction of hazardous effects to human health. Here, a sequential separation method with a fusion technique was developed to separate uranium and thorium isotopes from a soil sample using polymer resins (UTEVA® and TEVA®) packed columns. The radioactivity of separated U and Th was measured using alpha-particle spectrometry. The developed method was evaluated by assessing the key validation parameters of the selectivity, radioactivity range of linearity, scores for quality control, accuracy, tracer recovery yield, and quantification of uncertainty. The method offered a fast analysis of U and Th isotopes of the soil samples with very high chemical recovery yield and the effective removal of interferences, and demonstrated a satisfactory quality level for the selected criteria of the performance for the method validation. The developed method might be promising for use in a determination of the radioactivity of solid samples containing various interferences.


      PubDate: 2016-07-26T15:54:07Z
       
  • A novel core@shell magnetic molecular imprinted nanoparticles for
           selective determination of folic acid in different food samples
    • Abstract: Publication date: September 2016
      Source:Reactive and Functional Polymers, Volume 106
      Author(s): Sajjad Hussain, Sabir Khan, Saima Gul, Maria Isabel Pividori, Maria Del Pilar Taboada Sotomayor
      In this work, magnetic molecularly imprinted polymers (MMIPs) were synthesized and tested for the determination of folic acid (FA) in different food samples. The MMIPs were polymerized at the surface of Fe3O4@SiO2 magnetic nanoparticles (MNPs) using acrylonitrile (functional monomer), ethylene glycol dimethacrylate (EGDMA) as cross-linking agent and azobiisobutyronitrile (AIBN) as an radical initiator. The morphological, topological and chemical characteristics of the MMIPs were investigated by field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM) and Fourier transform infrared (FTIR) techniques. The physico-chemical characterization, such as adsorption capacities and selectivity of MMIPs was investigated and compared with the respective MNIPs. The adsorption experimental data demonstrate that maximum adsorption capacity of MMIP at equilibrium was 8mgg−1 and than the adsorption process of FA over MMIPs follows Freundlich adsorption isotherm model and pseudo-first-order reaction kinetic. For evaluation of this new proposed material, the recovery studies were carried out in spiked samples at different concentration levels and the obtained values were in the range of 95–104% for orange and for spinach the recoveries were between 99.5 and 102.5%. The relative standard deviations (RSD) for the recoveries were <0.5% for both samples. These results demonstrate that this novel MMIP material can be efficiently used for the selective extraction of folic acid from different food complex matrices.


      PubDate: 2016-07-26T15:54:07Z
       
  • Novel composites from green unsaturated polyesters and fly ashes:
           Preparation and characterization
    • Abstract: Publication date: September 2016
      Source:Reactive and Functional Polymers, Volume 106
      Author(s): A.S.M. Trino, C.S.M.F. Costa, A.C. Fonseca, I. Barata, E. Júlio, A.C. Serra, J.F.J. Coelho
      New composites from unsaturated polyesters (UPs), with high ‘green’ content, and fly ashes (FA) were studied for the first time. All the monomers used in the synthesis (fumaric acid, succinic acid, propylene glycol, 1,3-propanediol) can be obtained from renewable resources, with the exception of diethylene glycol. The composites were prepared by crosslinking the UPs in the presence of FA, using styrene (St), methyl methacrylate (MMA) and a mixture of acrylated epoxidized soybean oil (AESO) with St as reactive solvents. The results showed that the incorporation of the FA improved the thermal stability of the composites. Regarding the thermomechanical properties, it was found that the incorporation of 50% (w/w) FA led to composites with higher elastic modulus (E′) and higher glass transition temperature (T g) than the neat polymeric matrix. These observations indicate a good compatibility between the FA and the polymeric matrix.


      PubDate: 2016-07-26T15:54:07Z
       
  • Controlling the polymer-nanolayer architecture on anion-exchange membrane
           adsorbers via surface-initiated atom transfer radical polymerization
    • Abstract: Publication date: September 2016
      Source:Reactive and Functional Polymers, Volume 106
      Author(s): Jan Schwellenbach, Peter Kosiol, Björn Sölter, Florian Taft, Louis Villain, Jochen Strube
      The immobilization of a polymer-nanolayer containing ligand sites is a widely used approach to increase the binding capacity of membrane adsorbers. In this work strong anion-exchange membrane adsorbers were produced via surface-initiated atom transfer radical polymerization (SI-ATRP) using a monomer bearing a quaternary amine group (Q-type). Additionally the architecture of the polymer-nanolayer has been controlled with respect to the length and density of the grafted polymer chains and in terms of ligand density and interchain crosslinking degree. The influence of these architecture parameters on the membrane permeability and the static binding capacity towards bovine serum albumin (BSA) as a model protein has been investigated. It could be shown that these parameters have a major impact on the performance of the produced membrane adsorbers. While the chain-length and –density significantly increase the binding capacity, a decrease in permeability is observed. The interchain crosslinking degree and a reduction of the ligand density increase the permeability, but simultaneously the static binding capacity is slightly diminished. A well-chosen combination of these architecture parameters can produce membrane adsorbers with static binding capacities >100mg/mL membrane volume (MV) while still maintaining a specific permeability >40mL/(min·cm2·bar), far superior to commercially available products.


      PubDate: 2016-07-26T15:54:07Z
       
  • Synthesis and characterization of thermoset imidazolium bromide ionomers
    • Abstract: Publication date: Available online 26 July 2016
      Source:Reactive and Functional Polymers
      Author(s): Monika R. Kleczek, Ralph A. Whitney, Andrew J. Daugulis, J. Scott Parent
      Elastomeric ionomers are prepared via halide displacement from brominated poly(isobutylene-co-isoprene) (BIIR) with various imidazole-based nucleophiles. Reaction of BIIR with imidazole or 1,1′(1,4-butanediyl)bis(imidazole) in a single-step, solvent-free elastomer compounding approach is used to synthesize thermoset derivatives, in addition to a two-step process involving reaction of BIIR with 1-vinylimidazole (VIm), followed by peroxide-initiated cross-linking. The physical properties of these ionomeric thermosets are the product of their covalent and ionic networks. Ion-pair aggregation contributes significantly to dynamic storage modulus and low-strain static tensile modulus, but extensive relaxation of this labile network minimizes its influence over timescales larger than 1min. The adhesive properties and antibacterial activity against E. coli provided by these ionomers are also demonstrated.


      PubDate: 2016-07-26T15:54:07Z
       
  • Graphene oxide–enriched double network hydrogel with tunable
           physico-mechanical properties and performance
    • Abstract: Publication date: Available online 25 July 2016
      Source:Reactive and Functional Polymers
      Author(s): Sepideh Mohammadi, Hamid Keshvari, Mahnaz Eskandari, Shahab Faghihi
      An emerging approach to obtain polymeric hydrogels with superior properties is integrating carbon-based nanomaterials within their network structure. On the other hand, hydrogels with tailored physical and mechanical characteristics are desirable class of materials which have extensive application in drug delivery and tissue engineering. This study presents a strategy to achieve graphene oxide (GO)-enriched hydrogels with modulated physico-mechanical properties and performance. GO/poly acrylic acid (PAA)/gelatin hydrogels are fabricated via in situ polymerization method followed by chemical crosslinking of gelatin molecules. N,N′-Methylenebisacrylamide (BIS) in a various concentrations is used within the prepolymer composition as cross-linking agent to prepare a set of nanocomposite hydrogels. Fourier transform infrared (FTIR), X-ray diffraction (XRD), and atomic force microscopy (AFM) are utilized to characterize the fabricated hydrogel samples. The microstructure of samples is analyzed with scanning electron microscopy (SEM). The mechanical properties of the specimens are evaluated by rheometry. The swelling behavior, degradation kinetic and porosity of the hydrogels as well as their in vitro cytotoxicity are also assessed. The results show successful synthesis of nano GO sheets and polymer composites. The increase of cross-linker concentration is decreased the swelling ratio and increased the porosity of hydrogel samples. A wide range of pore diameters (70–300μm) and mechanical stiffness (storage modulus of 2000–25,000Pa) is obtained. Through manipulation of cross-linking density the degradation rate of nanocomposite hydrogels is controlled. Finally, no toxicity is detected by exposure of the hydrogel extracts to osteoblast osteosarcoma cells. The optimized hydrogel samples having appropriate range of physical characteristics and functionality suggest the application of the 3D structures as scaffold material for hard tissue construction.
      Graphical abstract image

      PubDate: 2016-07-26T15:54:07Z
       
  • Superb adsorption capacity and mechanism of
           poly(1-amino-5-chloroanthraquinone) nanofibrils for lead and trivalent
           chromium ions
    • Abstract: Publication date: Available online 25 July 2016
      Source:Reactive and Functional Polymers
      Author(s): Shaojun Huang, Chengzhang Ma, Yaozu Liao, Chungang Min, Ping Du, Yanqin Zhu, Yubo Jiang
      Poly(1-amino-5-chloroanthraquinone) (PACA) nanofibrils were applied as new nano-adsorbents for heavy metal removal from aqueous solutions. Adsorption properties including adsorption capacity, selectivity, kinetics, mechanism, and isotherm of PACA nanofibrils were studied in detail. The competitive adsorption of the nanofibrils for Pb(II) and Cr(III) in binary mixture systems was investigated. The results showed that Pb(II) and Cr(III) were adsorbed preferentially over the other metal ions including Hg(II), Cr(VI), Zn(II), Cd(II), Fe(III) and Cu(II), under competitive conditions. Kinetic data indicated that the adsorption process of PACA nanofibrils for Pb(II) and Cr(III) achieved equilibrium within 2 h following a pseudo-second-order rate equation and exhibiting a three-stage intraparticle diffusion mode. The adsorption mechanism of PACA nanofibrils for Pb(II) and Cr(III) was investigated by Fourier transform infrared spectra (FT-IR) and X-ray photoelectron spectroscopy (XPS) analyses. The adsorption isotherms of Pb(II) and Cr(III) fitted well with the Langmuir model, exhibiting superb adsorption capacity of 4.27 and 4.22 mmol of metal per gram of adsorbent, respectively. Furthermore, adsorption–desorption experiments demonstrated that the PACA nano-adsorbents could be easily recycled without considerable changes in the adsorption capacity.


      PubDate: 2016-07-26T15:54:07Z
       
  • A novel gelatin-AgNPs coating preparing method for fabrication of
           antibacterial and no inflammation inducible coatings on PHBV
    • Abstract: Publication date: Available online 25 July 2016
      Source:Reactive and Functional Polymers
      Author(s): Xingxing Zhao, Hairong Liu, Yibing Hu, Jiying Huang, Shuihan Zhang, Fei Ja
      Silver nanoparticles (AgNPs) based antibacterial materials are widely applied to commodity and clinic wound treatments. However, genotoxicity and inflammatory response induced by AgNPs inhibit their application as the antibacterial coating of medical devices like catheters. A novel gelatin-AgNPs coating manufacture method was introduced here to generate an antibacterial coating, which nearly immunes to inflammatory, on basal PHBV material. The novel gelatin-AgNPs coating was produced by immobilizing gelatin on the Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) membrane and subsequently fixing AgNPs on acquired gelatin coating. Prepared gelatin-AgNPs coatings displayed considerable antibacterial capacity. These gelatin-AgNPs coatings did not cause inflammation, growth inhibition or apoptosis to normal human embryonic lung fibroblasts, MRC-5 cells, by analyzing the transcription levels of relevant genes in these cells incubated with tested coatings for 4days. Hence, this novel gelatin-AgNPs coating manufacture method paved its way to apply in medical devices manufacture including catheters.


      PubDate: 2016-07-26T15:54:07Z
       
  • Epoxy-thiol thermosets modified by carbazole decorated hyperbranched
           poly(ethyleneimine) for optical applications
    • Abstract: Publication date: Available online 25 July 2016
      Source:Reactive and Functional Polymers
      Author(s): O. Korychenska, C. Acebo, M. Bezuglyi, A. Serra, V.J. Grazulevicius
      New epoxy-thiol thermosets containing carbazolyl moieties were prepared by adding different proportions of a hyperbranched poly(ethyleneimine) with carbazolyl terminated units to diglycidylether of bisphenol A/trimethylolpropane tris(3-mercaptopropionate) stoichiometric formulations. This carbazolyl decorated hyperbranched polymer was synthesized from commercially available hyperbranched poly(ethyleneimine) and N-glycidyl carbazole and was characterized by standard procedures. The influence of adding different proportions of the modifier to the formulation on the curing process was determined by calorimetry after the selection of the most adequate latent initiator, which was a urethane compound, named PDU-250. Its decomposition at a well-defined temperature liberates the amine that initiates the thiol-epoxy curing process. The materials obtained with different proportions of modifier were characterized by means of thermomechanical analysis. On increasing the proportion of modifier, the glass transition temperature and the damping characteristics increased, but the thermal stability and the homogeneity were reduced. The films obtained by curing the different formulations exhibited fluorescence maxima at 370–374nm. The fluorescence quantum yields were in the range of 17–32% and they decreased with the increase of the amount of the modifier in the materials.
      Graphical abstract image

      PubDate: 2016-07-26T15:54:07Z
       
  • RAFT polymerization and dually responsive behaviors of
           terpyridine-containing PNIPAAm copolymers in dilute solutions
    • Abstract: Publication date: Available online 22 July 2016
      Source:Reactive and Functional Polymers
      Author(s): Hongwei Zhou, Fengshou Liang, Jie Li, Xiaobin Ding, Aijie Ma, Weixing Chen, Chunyan Luo, Gai Zhang, Wei Tian, Ming Cheng, Benchuan Liao
      Introduction of new components is an effective way to gain new functionalities and to regulate the properties of responsive polymers. In the present work, a RAFT polymerization approach to terpyridine-containing poly(N-isopropyl acrylamide) (PNIPAAm) copolymers was developed and the dually responsive behavior of the obtained polymer to temperature variation and metal ions in dilute solutions were investigated. By utilizing RAFT polymerization, the molecular weight polydispersity index of the polymer can be reduced compared with the traditional free radical polymerization method. Due to the coexistence of thermosensitive component and terpyridine, the synthesized polymer is thermosensitive and metal ion sensitive. Further titration investigation revealed that this polymer may be utilized as a water-soluble and colorimetric sensor for Fe2+ and Fe3+ and the obvious color change from a colorless state to a purple state makes the polymer a potential sensor to detect Fe2+ and Fe3+ macroscopically by naked eye. Overall, the terpyridine-containing poly(N-isopropyl acrylamide) copolymers may enrich the family of terpyridine-containing polymers and provide some clues for developing new multi-responsive and multi-functional polymers.


      PubDate: 2016-07-26T15:54:07Z
       
  • Development of high dielectric polyimides containing bipyridine units for
           polymer film capacitor
    • Abstract: Publication date: Available online 22 July 2016
      Source:Reactive and Functional Polymers
      Author(s): Xinwen Peng, Wenhui Xu, Linlin Chen, Yichun Ding, Tianrou Xiong, Shuiliang Chen, Haoqing Hou
      Polymer dielectrics with high dielectric constant, low dielectric loss, high breakdown strength, and high temperature capability are attractive for applications such as capacitive energy-storage. Commercially available polymer dielectrics such as biaxially oriented polypropylene (BOPP), poly(ethylene terephthalate) (PET), poly(ethylene naphthalate) (PEN), polycarbonate (PC), and poly(vinylidene) fluoride (PVDF) can be just operated below 200°C. Great effort has been put into exploring high temperature polymer dielectrics to fulfill the demand of high temperature applications, such as the aerospace and military power supply. In this study, a series of polyimides containing bipyridine units with good dielectric performance and high temperature capability were prepared by using a newly synthesized diamine monomer, (5,5′-bis [(4-amino) phenoxy]-2,2′-bipyridine (BPBPA)). These polyimides possessed high dielectric constant of the as-synthesized polyimides can be up to7.2, the dielectric loss was <0.04, and the energy density was up to 2.77J/cm3. Furthermore, the polyimides exhibited high glass transition temperature (Tg) of 275–320°C and tensile strengths of 175–221MPa. These obtained polyimides promise potential applications in high temperature flexible polymer film capacitor operated at high temperature.


      PubDate: 2016-07-26T15:54:07Z
       
  • Facile tunning the morphology and porosity of a superwetting conjugated
           microporous polymers
    • Abstract: Publication date: Available online 22 July 2016
      Source:Reactive and Functional Polymers
      Author(s): Peng Mu, Hanxue Sun, Jiake Zang, Zhaoqi Zhu, Weidong Liang, Fucheng Yu, Lihua Chen, An Li
      A series of conjugated microporous polymers (CMPs) were synthesized via palladium-catalyzed Sonogashira-Hagihara crosscoupling polycondensation of N,N-bis(4-bromobenzyl)amine and 1,3,5-triethynylbenzene in different ternary solvents. The globular, tubular and amorphous CMP networks with different BET (Brunauer-Emmett-Teller) surface areas were obtained. Take advantages of superhydrophobic/oleophilic properties and micoporous morphological structures of the resulting CMPs, a CMPs-based mesh film and a flexible, superhydrophobic, transparent CMPs-based film were prepared, which exhibit good oil/water separation performance and moderate transmittance. In addition, due to its abundant porous feature and unique chemistry nature of the as-prepared N-containing CMPs, the removal of the dyes from water and iodine from organic solvent have been investigated. The results show that the CMP-3 possesses the highest adsorption capacities of 269mgg−1 for rhodamine B, 198mgg−1 for methyl orange and 218mgg−1 for iodine, respectively. This work provides a useful guidance for design and construction of porous CMPs materials for special applications.


      PubDate: 2016-07-26T15:54:07Z
       
  • Design, synthesis, characterization and magnetic studies of the
           metal-quinolate PHEMA-b-HQ polymer micelles
    • Abstract: Publication date: Available online 22 July 2016
      Source:Reactive and Functional Polymers
      Author(s): Rong Ren, Yanhua Wang, Weilin Sun
      Metal coordinated micelles based on the diblock copolymer PHEMA82-b-HQ78 were synthesized. The block PHQ with 8-hydroxyquinoline groups can coordinate with metal ions to form the crosslinked core for micellization, while the other block PHEMA in the shell of the micelle improves its solubility. The morphological characteristics and the coordinating interaction between the metal ions and the core segment were characterized by DLS and TEM. The magnetic measurement found that the Curie-Weiss temperature T θ of the metalized micelle was 56K and its hysteresis loop exhibited the typical ‘S′ shape with low H c and M r. at 5K, indicating that this micelle had the properties of soft ferromagnetic materials.


      PubDate: 2016-07-26T15:54:07Z
       
  • Synthesis, morphology investigation and thermal mechanical properties of
           dopamine-functionalized multi-walled carbon nanotube/poly(amide-imide)
           composites
    • Abstract: Publication date: Available online 22 July 2016
      Source:Reactive and Functional Polymers
      Author(s): Shadpour Mallakpour, Amin Zadehnazari
      Here, poly(amide-imide) (PAI) composites containing multi-walled carbon nanotubes (MWCNT) were synthesized with solution casting method. To improve the dispersion and compatibility with the polymer matrix the MWCNT was surface-modified with dopamine biomolecule under microwave irradiation. The prepared dopamine-functionalized MWCNT (MWCNT-Dop) was characterized for their structure, morphology, and thermal behavior employing Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis, field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). The results consistently confirmed the formation of dopamine functionalities on MWCNT. The MWCNT-Dop/PAI hybrid films were also characterized extensively using FT-IR and XRD techniques. The microstructure of the composites was studied by FE-SEM and TEM, in terms of the dispersion state of the nanotubes and the polymer-nanotube interface. The thermal behavior and mechanical properties of the resultant composites were also studied. In comparison with neat PAI, the MWCNT-Dop reinforced composites posses higher thermal stability, tensile strength and Young's modulus.


      PubDate: 2016-07-26T15:54:07Z
       
  • The synthesis and absorption dynamics of a lignin-based hydrogel for
           remediation of cationic dye-contaminated effluent
    • Abstract: Publication date: Available online 22 July 2016
      Source:Reactive and Functional Polymers
      Author(s): Chenghua Yu, Feng Wang, Chunhui Zhang, Shiyu Fu, Lucian A. Lucia
      Lignosulfonate-g-acrylic acid (LS-g-AA) hydrogels that possess superabsorbent capacity were synthesized by grafting acrylic acid (AA) on the backbone of lignosulfonate (LS) in the presence of N,N′-methylene-bis-acrylamide (MBA) as initiated by laccase/t-BHP(tert-butyl hydroperoxide). Specifically, the carboxylic acid groups introduced by grafting acrylic acid, significantly enhanced the absorption capacity of LS-g-AA hydrogels. In this case, methylene blue (MB) was the representative dye substrate to study absorption dynamics. It was found that the equilibrium absorption of MB reached 2013mg•g−1 while pH, absorption time, and initial MB concentration affected the overall absorption capacity. The absorption isotherms and kinetics obeyed standard Freundlich and pseudo-2nd-order models, respectively. Furthermore, preliminary desorption experiments were conducted in weak acid solution and showed that ~50% of the original MB could be removed over one rinse cycle.


      PubDate: 2016-07-26T15:54:07Z
       
  • Synthesis and characterization of imidacloprid microspheres for controlled
           drug release study
    • Abstract: Publication date: Available online 20 July 2016
      Source:Reactive and Functional Polymers
      Author(s): Qiaohong Zheng, Hongchun Li, Yongsheng Niu
      Polypropylene carbonate (PPC) was synthesized by the alternating copolymerization of carbon dioxide with propylene oxide (PO). Imidacloprid microspheres were prepared by emulsion solvent evaporation, PPC as the drug-carrier material. The effect of the reaction conditions on drug loading (DL) and entrapment efficiency (EE) was examined. High DL of 45.03% was achieved at the methylene chloride and water volume ratio of 1:1, polyvinyl alcohol (PVA)-1788 concentration of 1%, imidacloprid and PPC mass ratio of 1:3, and shear rate of 10,000r/min. When imidacloprid and PPC mass ratio was 2:3, high EE of 77.91% was obtained. Through the scanning electronic microscopy (SEM) the hollow structure of the microspheres was studied. The effects of shear rate on the diameter and morphology of microspheres were studied by the SEM. The perfect microspheres were obtained at the 10,000r/min shear rate. The release behavior of imidacloprid encapsulated in the microspheres was studied. The experimental results indicated that the microspheres had a property of sustained drug release.


      PubDate: 2016-07-26T15:54:07Z
       
  • Thiol-ene-clickable and emissive carbazole-based polymer networks with
           tunable colors
    • Abstract: Publication date: September 2016
      Source:Reactive and Functional Polymers, Volume 106
      Author(s): Ceylan Doyranli, Sümeyra Büyükçelebi, Sermet Koyuncu, Özlem Usluer, Mahmut Kus, Fatma Baycan Koyuncu
      Band gap tuning and processability of organic materials are significant topics for both scientific research and commercial applications. In this study, we synthesized a series of main chain cross-linkable polymers by thiol-ene click chemistry from N-allyl carbazole and different heterocycles via conventional Suzuki coupling polymerization reaction. The emission color of polymers could be successfully tuned from blue to red by attaching different benzazole-acceptor moieties to the carbazole donor unit. We also investigated the effects of cross-linking with respect to the amount of pentaerythritol tetrakis(3-mercaptopropionate) cross-linker on the optical, electrochemical, and surface morphological properties of the polymer films. The results showed that these polymers can be used as emissive active layers in solution-processable multilayer organic light-emitting diodes.


      PubDate: 2016-07-19T15:02:51Z
       
  • Editorial Board
    • Abstract: Publication date: August 2016
      Source:Reactive and Functional Polymers, Volume 105




      PubDate: 2016-07-19T15:02:51Z
       
  • Development of Crystal Violet encapsulation in pectin - Arabic gum gel
           microspheres
    • Abstract: Publication date: Available online 11 July 2016
      Source:Reactive and Functional Polymers
      Author(s): Mariana V. Revuelta, M. Elizabeth Chacon Villalba, Alba S. Navarro, Jorge A. Güida, Guillermo R. Castro
      Six pectins with 35% to 91% methoxylation degree were purified and characterized to encapsulate Crystal Violet (CV). Amidated low methoxylated pectin (ALMP) was selected based on microsphere morphologies, aqueous solubility, viscosity and the effect of calcium concentration. Pectin microspheres were stabilized with Arabic gum (AG) and optimized according to the loading. Microspheres composed of 2.0% ALMP-1.0% AG crosslinked with 450mM calcium(II) were able to encapsulate 217±2μM CV. Optical microscopy of the gels revealed spheroid microspheres with 250±50μm diameter containing homogenous CV distribution. Dried microspheres observed by SEM and epifluorescence showed a highly shrinkable matrix keeping the spheroidal morphology. Low relative viscosity of the ALMP-AG-CV solutions was found compared to ALMP and ALMP-AG. The Young moduli (60–80Pa) of ALMP-AG microspheres by texturometric analysis indicated that the CV could interfere with the gel crosslinking. Raman spectroscopy analysis suggested some interaction of CV nucleophilic center within the matrix. FTIR of the matrix showed largest shifts in the carbonyl and carboxylate groups probably associated to H-bridges. CV stability studies performed on ALMP-AG microspheres, synthetized from polymer solutions with pH values above and below pectin pKa and showed faster CV release rates in presence of ionic strength.


      PubDate: 2016-07-14T14:20:35Z
       
  • Methylene blue removal by alginate–clay quasi-cryogel beads
    • Abstract: Publication date: September 2016
      Source:Reactive and Functional Polymers, Volume 106
      Author(s): Güler Uyar, Hakan Kaygusuz, F. Bedia Erim
      Nowadays, dyes constitute a large part of pollutants and have long been used in dyeing, paper and pulp, textiles, plastics, leather, cosmetics, and food industries. Among the conventional dye removal techniques, adsorption is prominent. Research challenges are on developing low-cost, biodegradable and efficient adsorbents. This study investigates polysaccharide–clay composite beads for the removal of methylene blue dye. Alginate–montmorillonite composite beads were prepared and then a novel cryogelation-like strategy was developed by deep-freezing the alginate beads at −21°C. This process changed the morphology of beads and improved surface area and adsorption capacity. The results of the batch adsorption experiments were modeled using isothermal, kinetic, and thermodynamic models. It is found that the adsorption is favorable and follows physical mechanism, with an endothermic process up to 40°C. The prepared composite beads are candidates for effective adsorbents for the dye removal.


      PubDate: 2016-07-09T13:14:32Z
       
  • Bio-based high performance epoxy-anhydride thermosets for structural
           composites: The effect of composition variables
    • Abstract: Publication date: August 2016
      Source:Reactive and Functional Polymers, Volume 105
      Author(s): Adlina Paramarta, Dean C. Webster
      The structure-property relationships of a designed series of anhydride-cured epoxidized sucrose soyate (ESS) thermosets were studied. Epoxidized sucrose soyate is a novel bio-based epoxy resin derived from sucrose and soybean oil fatty acids, and it contains an average of 12 epoxy functional groups per molecule. This epoxy resin was crosslinked with methyl hexahydrophthalic anhydride to form polyester thermosets with high crosslink density, and a zinc-complex catalyst was used. In this study, the impact of composition variables—anhydride-to-epoxy molar ratio and catalyst amount—on the chemical, mechanical, and thermal properties of the thermosets was examined. All of the thermoset samples had very high gel fraction, which indicated excellent network connectivity. Samples made using an equimolar ratio of anhydride-to-epoxy groups had lower conversion of functional groups as shown by the somewhat lower gel fraction and higher moisture absorption. Analysis of the thermomechanical and tensile properties of the thermosets suggests that there is a factor interaction between anhydride-to-epoxy molar ratio and catalyst amount. Furthermore, the results suggest that the molecular networks of the thermoset samples are fairly complex due to the simultaneous competing reactions between catalyst-initiated epoxy-anhydride, hydroxyl-initiated epoxy-anhydride, and epoxy homopolymerization.


      PubDate: 2016-07-09T13:14:32Z
       
  • Self-Organization and Phase Transformation of All π-Conjugated
           Diblock Copolymers and Its Applications in Organic Solar Cells
    • Abstract: Publication date: Available online 18 June 2016
      Source:Reactive and Functional Polymers
      Author(s): Ching Shen, Yi-Huan Lee, Yu-Ping Lee, Chi-Ju Chiang, Fan-Kai Wei, Chia-Hung Wu, Kuo-Chang Kau, Hung-Wei Liu, Chih-Chen Hsieh, Leeyih Wang, Chi-An Dai
      In this study, we report on the synthesis and the self-assembling behavior of a series of monodisperse all π-conjugated poly(2,5-dihexyloxyp-phenylene)-block-(3-hexylthiophene) (PPP-P3HT) block copolymer system and construct their phase diagram that exhibits diverse nanostructures of predominant PPP nanofibers, PPP-P3HT lamellae, broken lamellae and predominant P3HT nanofibers as a function of the copolymer composition. An order-to-disorder phase transition is also observed for the copolymers at a temperature above the melting point of the predominant blocks, indicating the rod-rod interaction between the π-conjugated chains plays a key role in the formation and the stabilization of the observed nanostructures. In particular, we have also found that the incorporation of PPP segments to P3HT to form nanofibrillar structure significantly enhance the self-organization behavior of the P3HT in the copolymer. The improvements in crystallinity and mobility for the copolymers therefore substantially enhance their solar cell performance. The use of this novel material with diverse nanostructures provides a new strategy to enhance photovoltaic performance and shows the potential for use in future optoelectronic applications.


      PubDate: 2016-06-18T18:05:28Z
       
  • Poly(ionic liquid) Prepared by Photopolymerization of Ionic Liquid
           
    • Abstract: Publication date: Available online 18 June 2016
      Source:Reactive and Functional Polymers
      Author(s): Shen-Mei Chen, Tzong-Liu Wang, Pei-Yu Chang, Chien-Hsin Yang, Yi-Chao Lee
      Vinylimidazolium-typed poly(ionic liquids) (PILs) are prepared by photo- polymerization of ionic liquid monomers. Vinylimidazolium-based ionic liquid monomers with C4 and C8 alkyl tail length were synthesized via quaternization of 1-vinylimidazole with corresponding n-alkyl bromides. Polymerization was conducted at a 3wt% of photoinitiators in these monomers using illumination of 36W LED light. In the same procedure, preparation of cross-linked PILs was performed in the presence of 15 mole % of divinylimidazolium-based cross-linker. These PILs are characterized by using chemical structure, physical characteristics, and electrical conductivity. Electrical conductivity of C4-based PILs is greater than that of C8 -based PILs, whereas linear PILs are higher than crosslinked PILs. Crosslinked PILs have higher glass transition and thermal decomposition temperatures as compared linear PILs. PILs consist of the repeating units of anion and cation pair. Its nature has moderate electronic conductivity, which is suitable use in gel-type or quasi-solid-state dye-sensitized solar cells (DSSCs). The linear PILs were incorporated in DSSCs obtaining an efficient quasi-solid-state cell to solve the leakage of liquid electrolyte in a liquid-type DSSC.


      PubDate: 2016-06-18T18:05:28Z
       
  • Structure of hydrogen bonded supramolecular self-assembles controlled by
           the structure of monomers: 1,1- and 1,3-diethylureas
    • Abstract: Publication date: Available online 7 June 2016
      Source:Reactive and Functional Polymers
      Author(s): Jolanta Świergiel, Jan Jadżyn
      Asymmetrically disubstituted 1,1-diethylurea, the moiety HNH·CO of which is capable of forming intermolecular hydrogen bonds with the possibility of creating two extremely different supramolecular entities: i) highly polar polymeric chains, analogous to those created by secondary amides, and ii) non-polar cyclic dimers, analogous to those created by lactams, in the experiment reveals exclusively the cyclic dimers. A solution of 1,1-diethylurea in non-polar solvent (with the mole fraction of urea 0.04) exhibits very low permittivity (about 3) what is in marked contrast to the permittivity (about 11) of analogous solution of symmetrically disubstituted 1,3-diethylurea, known for its strong chain polymerization.The difference of two orders of magnitude in the electrical conductivities of 1,1- and 1,3-diethylurea (ionically undoped) solutions suggests a probable participation in the conductivity of the protons released in process of thermal rupture of the hydrogen bonds linking 1,3-diethylurea molecules in supramolecular polymeric chains.


      PubDate: 2016-06-15T13:31:59Z
       
  • MALDI-TOF analysis of lactide oligomers with functional end groups
    • Abstract: Publication date: July 2016
      Source:Reactive and Functional Polymers, Volume 104
      Author(s): Marcin Florczak, Adam Michalski, Anna Kacprzak, Marek Brzeziński, Tadeusz Biedroń, Agnieszka Pająk, Przemysław Kubisa, Tadeusz Biela
      Medium molecular weight polylactides (PLAs) with different end groups were synthesized and analyzed by matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry. Four types of end groups were introduced as head group using appropriate initiators: cationic group [ionic liquid group (IL-PLA-OH)], easily ionizable groups [aminopyridine group (AmPy-PLA-OH) and terpyridine group (TerPy-PLA-OH)], and neutral group [butoxy group (Bu-PLA-OH)]. MALDI-TOF spectra were recorded with various cationizing agents (Li+, Na+, and K+ salts). Different modes of ionization were observed depending on the nature of end group. These various modes of ionization lead to different ionization efficiencies, which affect signal intensity. Moreover, analysis of 1/1 mixtures showed that in spectra of mixtures of IL-PLA-OH with either AmPy-PLA-OH or Bu-PLA-OH, only the signals of IL-PLA-OH were detected, while in the spectrum of AmPy-PLA-OH with Bu-PLA-OH, the former gave signals with intensity about one order of magnitude higher than the latter. Such discrimination resulting from different modes and efficiencies of ionization of macromolecules containing structurally different end groups may lead to erroneous conclusions.


      PubDate: 2016-06-15T13:31:59Z
       
  • Linear amphiphilic TEMPO-grafted poly(ether sulfone) as polymeric
           interfacial catalyst: Synthesis, self-assembly behavior, and application
    • Abstract: Publication date: Available online 15 June 2016
      Source:Reactive and Functional Polymers
      Author(s): Liang Chen, Jun Tang, Qi Zhang, Jianli Wang
      In this study, we report the development of a novel recyclable polymer-supported interfacial catalyst for Montanari oxidation. The catalyst was prepared by immobilization of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) on poly(ether sulfone) (PES) bridged by imidazole groups and characterized by 1H nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, elemental analysis, contact angle measurement, and transmission electron microscopy (TEM). This well-designed polymer was self-assembled into nanoaggregates in CH2Cl2. It was then used as Pickering emulsifier in Montanari oxidation system (NaClO/NaBr/immobilized TEMPO) for selective oxidation of different alcohols, which exhibited higher activity due to the enhanced mass transfer through microreactor mechanism. Moreover, this polymeric interfacial catalyst was pH-sensitive and could be easily recycled by adding small amount of acid, and subsequent cycles of alcohol oxidation showed no loss on either conversion or selectivity. This study represents an innovative approach for developing polymeric interfacial catalyst.
      Graphical abstract image

      PubDate: 2016-06-15T13:31:59Z
       
  • Editorial Board
    • Abstract: Publication date: July 2016
      Source:Reactive and Functional Polymers, Volume 104




      PubDate: 2016-06-15T13:31:59Z
       
  • Editorial Board
    • Abstract: Publication date: June 2016
      Source:Reactive and Functional Polymers, Volume 103




      PubDate: 2016-06-15T13:31:59Z
       
  • Deposition of Au nanoshells on thermally grown patterned Ag nanoparticles
           from the block copolymer micelle thin films by seeding method
    • Abstract: Publication date: August 2016
      Source:Reactive and Functional Polymers, Volume 105
      Author(s): Himadri Acharya
      A facile method of fabricating patterned Ag–Au core–shell nanoparticles has been demonstrated using stepwise reduction and seeded deposition from block copolymer (BCP) micelle thin films. Spherical inverse micelles of polystyrene-block-poly(4-vinyl pyridine) (PS-b-P4VP) copolymer in PS-selective toluene produce organic–inorganic complexes by coordinating silver acetate salt (Ag salt) to the hydrophilic P4VP core. Rapid thermal decomposition of Ag salt-loaded BCP micelles at 300°C for 5min leads to the formation of stable Ag nanoparticles of 20–25-nm size on a quartz substrate. The variations in annealing temperature, time, and substrate types influence the resulting Ag nanostructures. Transmission electron microscopy investigations reveal that gold (Au) shells of approximately 2.5-nm size on the Ag nanoparticles have been deposited by the seeding method using a selective reducing agent. Ag–Au core–shell nanoparticles can also help to control the hybridized surface plasmon band.


      PubDate: 2016-06-15T13:31:59Z
       
  • Adsorption and release studies of cefuroxime sodium from acrylic ion
           exchange resin microparticles coated with gellan
    • Abstract: Publication date: August 2016
      Source:Reactive and Functional Polymers, Volume 105
      Author(s): S. Racovita, M.A. Lungan, I. Bunia, M. Popa, S. Vasiliu
      Two types of microparticles based on acrylic ion exchange resin were prepared and used as macromolecular supports for the adsorption of an antibiotic (cefuroxime sodium salt) from aqueous solution. The first type of microparticles was synthesized by aqueous suspension copolymerization of acrylonitrile, ethylacrylate and ethylene glycol dimethacrylate followed by the aminolysis reaction of ternary copolymer with hydrazine hydrate. For the preparation of the second type of microparticles the gellan was selected to cover the surface of acrylic ion exchanger in order to increase the biocompatibility of these systems. Batch adsorption studies regarding the effects of various parameters such as, temperature, contact time, initial concentration of drug, drug:microparticles ratio and pH were studied. To study the adsorption kinetic mechanism, the Lagergren, Ho, Elovich and Weber-Morris particle diffusion models were applied and it was found that the adsorption of the drug could be described by pseudo first order equation (Lagergren model). The calculated values of thermodynamic parameters (ΔG, ΔH, ΔS) showed that the adsorption process was spontaneous and endothermic. The drug release process was found to be controlled by diffusion of drug molecules through polymer networks.


      PubDate: 2016-06-15T13:31:59Z
       
  • Energy-level tuning of poly(p-phenylenebutadiynylene) derivatives by click
           chemistry-type postfunctionalization of side-chain alkynes
    • Abstract: Publication date: August 2016
      Source:Reactive and Functional Polymers, Volume 105
      Author(s): Dong Wang, Ruirui Zhang, Hong Gao, Xiangke Wang, Huihui Wang, Zhou Yang, Wanli He, Hui Cao, Jianming Gu, Huiying Hu, Huai Yang
      A series of poly(p-phenylenebutadiynylene) polymers substituted with electron-rich alkynes as the side chain were synthesized by homocoupling polymerization of asymmetric bifunctional monomers. The electron-rich alkynes underwent “click chemistry” with tetracyanoethylene (TCNE) to produce donor–acceptor chromophores. Optical and electrochemical characterizations clearly indicated that the energy level and band gap of P2 could be precisely controlled by the addition of acceptor molecules. One of the most important conclusions of this study is that a linear relationship between the lowest occupied molecular orbital (LOMO) and the amount of TCNE was observed. From the Z-scan measurement, all the compounds exhibited very special nonlinear optical properties, which suggested a tendency to transfer from saturable absorption (SA) to reverse saturable absorption (RSA).


      PubDate: 2016-06-15T13:31:59Z
       
  • Ultrafast and efficient removal of cationic dyes using a magnetic
           nanocomposite based on functionalized cross-linked poly(methylacrylate)
    • Abstract: Publication date: August 2016
      Source:Reactive and Functional Polymers, Volume 105
      Author(s): Ali Pourjavadi, Azardokht Abedin-Moghanaki
      In this study, a new magnetic nanocomposite was synthesized via radical polymerization of methyl acrylate onto modified magnetic nanoparticles followed by the functionalization of the methyl ester groups with ethylenediamine and sodium chloroacetate. The generated magnetic nanocomposite was characterized by FT-IR, TEM, SEM, TGA, VSM, XRD and elemental analysis. Its key role as an adsorbent for the removal of typical cationic dyes, methyl violet and malachite green was investigated in terms of pH, contact time and initial dye concentration. The resulted adsorbent displays excellent adsorption capacities for cationic dyes which are more effective than most of the adsorbents reported so far. Study of the kinetic and isotherm of adsorption indicated that dyes adsorption process is well-described by pseudo-second-order-kinetic and Langmuir isotherm models, respectively. Furthermore, to find an accurate correlation between the adsorption enthalpy (ΔH) and experimental maximum adsorption capacity (qm), calculation of the adsorption enthalpy of a series of cationic dyes onto MNC-EDDA adsorbent was investigated using density functional theory (DFT). Interestingly, an excellent agreement between experimental qm and calculated ΔH (kcal/mol) was found which is able to predict the maximum adsorption capacities onto the prepared adsorbent for the other cationic dyes.


      PubDate: 2016-06-15T13:31:59Z
       
  • Evaluation of the use of solvent impregnated resins in the analysis of
           salbutamol in human urine followed by capillary electrophoresis
    • Abstract: Publication date: August 2016
      Source:Reactive and Functional Polymers, Volume 105
      Author(s): Irma Pérez-Silva, Ma. Teresa Ramírez-Silva, Carlos A. Galán-Vidal, Giaan A. Álvarez-Romero, José A. Rodríguez, Ma. Elena Páez-Hernández
      In this work, a method for sorption and concentration of salbutamol in urine combined to capillary electrophoresis with UV detection was performed. The procedure is based on the sorption of salbutamol on solvent-impregnated resins that is prepared by an impregnation technique using Aliquat 336 as extractant and XAD-4 resin as the base polymer. Batch studies showed an efficient sorption/desorption results when the salbutamol solution contains NaOH 0.05molL−1 and the eluent is 0.5molL−1 NaCl. Linearity was obtained in the range of 1000–10,000ngmL−1 of salbutamol. The limit of quantification was 999ngmL−1. The solvent-impregnated resin was used for 10cycles without a significant loss of the salbutamol quantification capacity. The method was applied to analyze salbutamol in urine samples at levels useful for international health organizations. Although most reports of solvent impregnated resins are related to the extraction of metal ions and only a few organic compounds, the proposed methodology demonstrate that solvent impregnated resins allows the isolation and concentration of salbutamol from complex samples such as urine. Since no SB is recovered using resin without Aliquat 336, this work shows an advantage of SIR over simple adsorption processes.


      PubDate: 2016-06-15T13:31:59Z
       
  • Preparation of polyaniline-coated polystyrene nanoparticles for the
           sorption of silver ions
    • Abstract: Publication date: August 2016
      Source:Reactive and Functional Polymers, Volume 105
      Author(s): Saurabha Bhattarai, Jong Soo Kim, Yeoung-Sang Yun, Youn-Sik Lee
      Polyaniline-coated polystyrene (PS/PANI) beads with an average diameter of approximately 310nm were prepared from styrene and divinylbenzene via emulsion polymerization and subsequent oxidative polymerization of aniline. The sorption capacity of the polymer beads towards silver ions in aqueous solution increased substantially as the pH increased, up to a pH of 7, owing to more free amine and imine groups. The FE-SEM images and XRD data indicated that silver ions were reduced to form silver nanoparticles on the polymer beads. The kinetics of silver ion uptake by PS/PANI particles in a 160ppm silver nitrate solution could be described by a pseudo-second order model. Even though the sorption isotherm correlated to the Freundlich model much better than the Langmuir model, the Langmuir model-based maximum sorption (320mgg−1) was closer to the experimentally obtained value of 330mgg−1. This study reveals that PS/PANI beads can be readily prepared in large quantities and employed as one of most efficient sorbents of silver ions in the aqueous phase. The high sorption capacity of the polymer nanoparticles was illustrated not to be affected by common alkali and alkaline earth metal ions in a simulated tap water. The PS/PANI nanoparticles were stable enough not to show any significant loss in sorption efficiency even after fourth cycle of adsorption-desorption.
      Graphical abstract image

      PubDate: 2016-06-15T13:31:59Z
       
  • A review of the fabrication of photonic band gap materials based on
           cholesteric liquid crystals
    • Abstract: Publication date: August 2016
      Source:Reactive and Functional Polymers, Volume 105
      Author(s): Rathinam Balamurugan, Jui-Hsiang Liu
      Cholesteric liquid crystals (CLCs) are known to exhibit selective reflection of incident radiation due to their periodic helical structure, which makes them promising candidates for a myriad of different photonic applications. At normal incidence, CLCs reflect circularly polarized incident light of the same handedness as the cholesteric helix and of wavelength λ between noP and neP, where no and ne are the ordinary and extraordinary refractive indices, respectively, of the locally uniaxial structure, and P is the pitch of the helix. Thus, the reflection bandwidth Δλ is given by Δλ=ΔnP, where the birefringence Δn=ne −no. Within the bandwidth, right-circularly polarized light is reflected by a right-handed helix, whereas left-circularly polarized light is transmitted. Outside the bandwidth, both polarization states are transmitted. Therefore, Δλ depends on Δn. Moreover, Δn is typically limited to 0.3–0.4 for colorless organic compounds, and Δλ is often <100nm in the visible spectrum. Although a narrow reflection band is desirable for applications such as optical filters and thermal imaging, it also becomes a drawback in their applications, such as reflective displays, broadband circular polarizers and switchable mirrors. The purpose of this review is to take a closer look into how to broaden the reflection band in CLCs to overcome the above limitations for a wide variety of applications. This review covers the methodology that was used until recently, when the fabrication of photonic band gap (PBG) materials arose, based on CLCs. The mechanisms for broadening the reflection band have been reviewed.


      PubDate: 2016-06-15T13:31:59Z
       
  • Architecture of Ba/alginate/dextran stabilized Au, Fe3O4, TiO2 &amp;
           silica nanoparticles gels and their applications for reduction of
           4-nitrophenol and glucose sensing
    • Abstract: Publication date: August 2016
      Source:Reactive and Functional Polymers, Volume 105
      Author(s): Molly Thomas, Gowhar Ahmad Naikoo, Mehraj Ud Din Sheikh, Mustri Bano, Farid Khan
      An innovative method is presented to produce anisotropically ordered capillaries and small pores by dissipative convective process followed by simple freezing in liquid nitrogen of Ba/alginate/dextran hydrogels with and without nanoparticles. Magnetite, gold, silica or titanium dioxide nanoparticles were encapsulated safely into the gels with protecting their stability and microstructures. Mechanical strength and rheological studies of the gels were also investigated. Ba/alginate/dextran/Au composite gel has shown excellent catalytic activity for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in presence of NaBH4 with a rate constant of 6.85×10−3 min−1. Ba/Alg/Dex/Au-GCE exhibits non-enzymatic electrocatalytic oxidation of glucose with linear range from 1mM to 10mM (r=0.998) and the detection limit to 63μM at a signal-to-noise ratio of 3.


      PubDate: 2016-06-15T13:31:59Z
       
  • Multi-stimuli-responsive semi-IPN cryogels with native and anionic potato
           starch entrapped in poly(N,N-dimethylaminoethyl methacrylate) matrix and
           their potential in drug delivery
    • Abstract: Publication date: August 2016
      Source:Reactive and Functional Polymers, Volume 105
      Author(s): Ecaterina Stela Dragan, Diana Felicia Apopei Loghin, Ana-Irina Cocarta, Mirela Doroftei
      This study was focused on the preparation of novel multi-stimuli-responsive semi-interpenetrating polymer networks (semi-IPN) hydrogels by cross-linking polymerization of N,N-dimethylaminoethyl methacrylate (DMAEM) in the presence of potato starch (PS) or anionically modified PS by using ice-templating strategy (−18°C). Cryogelation was used for this aim because it allowed decreasing the monomer concentration to 10wt.% and a very fast response at swelling of the composite gels. Furthermore, the anionically modified PS allowed the decrease of the volume phase transition temperature (VPTT) of the composite cryogels by its electrostatic interactions with the matrix. After the characterization of the composite structure by Fourier transform infrared spectroscopy and of the macroporous morphology by scanning electron microscopy analysis, the effect of the entrapped polysaccharide on the swelling properties of the composite cryogels, and their response at three stimuli (pH, temperature and ion nature and concentration) were deeply investigated. The VPTT of the composite cryogels was situated in the range 36–39°C, the particular value depending on the DMAEM concentration and on the nature and content of polysaccharide. After that, diclofenac sodium (DS), taken as a model acidic drug, was easily loaded into the composite cryogels by the solvent sorption–evaporation strategy due to the interconnected pores of these materials. The controlled delivery of DS from the novel semi-IPN composite cryogels was then optimized by the investigation of the effects of pH, temperature, and cycling changes of the release temperature. It was found that these composite cryogels are promising systems for the sustained delivery of DS in the simulated intestinal fluid, but not in the simulated gastric fluid, and this recommends them as vehicles of drugs in colon. Finally, the release mechanism of DS from the composite cryogels was discussed based on two kinetic models.


      PubDate: 2016-06-15T13:31:59Z
       
  • Conducting semi-interpenetrating polymeric composites via the preparation
           of poly(aniline), poly(thiophene), and poly(pyrrole) polymers within
           superporous poly(acrylic acid) cryogels
    • Abstract: Publication date: August 2016
      Source:Reactive and Functional Polymers, Volume 105
      Author(s): Nurettin Sahiner, Sahin Demirci
      In this study, a novel and special form of hydrogel known as cryogel with super and interconnected pore structures was synthesized as p(acrylic acid) (p(AAc)) cryogel by a cryopolymerization technique. Then, the superporous p(AAc) cryogels were used as template for the synthesis of conductive polymers such as poly(aniline) (p(An)), poly(thiophene) (p(Th)), and poly(pyrrole) (p(Py)). To the best of the authors' knowledge, this is the first study of its kind to report the synthesis of conductive polymers, p(An), p(Th), and p(Py), within the superporous network of cryogel. The synthesized p(AAc)/p(An), p(AAc)/p(Th), and p(AAc)/p(Py) conducting semi-interpenetrating polymeric network (semi-IPN) cryogel composites were characterized by using Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), and conductivity measurements. The conductivities of p(AAc)/p(An), p(AAc)/p(Th), and p(AAc)/p(Py) toward semi-IPN cryogels were measured as 2.2×10−4 ±1×10−5, 3.2×10−4 ±0.9×10−5, and 3.2×10−3 ±5×10−4 Scm−1, whereas the conductivity of bare p(AAc) cryogels was calculated to be about 3.2×10−9 ±2.1×10−10 Scm−1.


      PubDate: 2016-06-15T13:31:59Z
       
  • Utility of PCDTBT polymer for the superior sensing parameters of
           electrical response based relative humidity sensor
    • Abstract: Publication date: August 2016
      Source:Reactive and Functional Polymers, Volume 105
      Author(s): Qayyum Zafar, Khaulah Sulaiman
      In the present study, organic polymer PCDTBT has been deposited on pair of planar aluminium (Al) electrodes to construct an integrated capacitive and impedance type humidity sensor (Al/PCDTBT/Al). The solution processable organic polymer has been deposited through a facile spin coating technique. The structural characterization and surface morphology study of active layer has been performed by XRD and AFM. The humidity sensing characteristics of the sensor have been investigated by exposing the organic active layer to various wide range relative humidity (%RH) levels (15–98%RH) at room temperature. The proposed sensor exhibits significantly higher sensitivity ~39.73pF/%RH and 821.81kΩ/%RH when operated in capacitive and impedance mode, respectively. In addition, the capacitive sensor has desirable reproducibility, narrow hysteresis (~5%), fast response (8s) and reset (14s) time. Significantly improved sensing parameters suggest that the proposed sensor may be implemented meritoriously for continuous humidity assessment in environment.


      PubDate: 2016-06-15T13:31:59Z
       
  • Metal nanoparticles designed PET: Preparation, characterization and
           biological response
    • Abstract: Publication date: August 2016
      Source:Reactive and Functional Polymers, Volume 105
      Author(s): A. Reznickova, J. Siegel, N. Slavikova, Z. Kolska, M. Staszek, V. Svorcik
      In this manuscript, Ar plasma treated polyethyeterephthalate grafted with biphenyl-4,4′-dithiol interlayer and subsequently with green synthesized Pt and Pd nanoparticles is studied, focusing on the cytocompatibility of those composites. Changes in surface properties of the plasma treated and nanoparticle-grafted PET surface were studied in relation to in vitro adhesion and proliferation of mouse fibroblasts (L929) and human osteoblast (U-2 OS). Prepared samples were studied by several experimental techniques: goniometry, angle resolved X-ray photoelectron spectroscopy (ARXPS), ultraviolet–visible spectroscopy (UV–vis), Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray spectroscopy (EDS) and electrokinetic analysis. Ageing of the modified PET was accompanied by an increase of the contact angle which was due to a reorientation of the molecular polar segments produced during the plasma treatment. FTIR, UV–vis, ARXPS measurements and zeta potential indicate that the thiols were chemically bonded to the surface of the plasma treated polymers and that the thiols mediate subsequent grafting of Pt and Pd nanoparticles. Generally, EDS revealed that Pt nanoparticles are homogeneously distributed over the whole surface and Pd nanoparticles tend to aggregate slightly. In case of L929 cells, the chemical anchoring of Pt nanoparticles to PET surface significantly enhanced cell adhesion and proliferation compared to pristine PET.
      Graphical abstract image

      PubDate: 2016-06-15T13:31:59Z
       
  • Covalent Biofunctionalization of Chitosan Nanofibers with Trypsin for High
           Enzyme Stability
    • Abstract: Publication date: Available online 12 May 2016
      Source:Reactive and Functional Polymers
      Author(s): Jana Srbová, Marcela Slováková, Zuzana Křípalová, Monika Žárská, Martina Špačková, Denisa Stránská, Zuzana Bílková
      The electrospun chitosan nanofibers provide excellent material for immobilized proteolytic enzymes, and are biocompatible, nontoxic and hydrophilic matrices with large specific area. This paper deals with an application of electrospun chitosan nanofibers and optimizing conditions for their biofunctionalization by model proteolytic enzyme trypsin. Nanofibers from chitosan were prepared using NanospiderTM technology and covalent immobilization of trypsin followed. Three immobilization techniques preserving biocompatibility and utilizing amine and/or hydroxyl groups of chitosan were optimized and compared to simple adsorption to achieve maximum proteolytic activity per cm2 of the functionalized chitosan nanofibers (Tryp-NF). Significant differences were observed. Trypsin immobilized by the carbodiimide one-step protocol demonstrated the highest activity of the three procedures, ranging from 132 to 210IU/cm2 (i.e., 548–874IU/mg of nanofibers), depending on the initial amount of trypsin used. Long-term storage stability together with high reusability of Tryp-NF confirmed advantages of the immobilized enzyme. Tryp-NF showed no cytotoxicity toward growth of HeLa cells. The in vivo tests for irritation and skin sensitization demonstrated no undesirable skin reactions.


      PubDate: 2016-05-16T19:02:11Z
       
  • Preparation and Application of Poly(AMPS-co-DVB) to Remove Rhodamine B
           from Aqueous Solutions
    • Abstract: Publication date: Available online 7 May 2016
      Source:Reactive and Functional Polymers
      Author(s): Luanluan Zhang, Hejun Gao, Yunwen Liao
      A series of functional cross-linked polymer (Poly(AMPS-co-DVB)) were synthesized by 2-acrylamido-2-methylpropane sulfonic acid (AMPS) and divinylbenzene (DVB). The physicochemical properties of the Poly(AMPS-co-DVB) were characterized by FT-IR, TGA, SEM, XRD, Zeta potential and UV–Vis. Those results showed that the Poly(AMPS-co-DVB) could provide mounts of adsorption sites from its special structure. The effects of the initial pH, dosage, contact time, and temperature on the adsorption of Rhodamine B (RhB) onto the Poly(AMPS-co-DVB) were investigated. It was found that the initial pH was an important factor for the molecules form of RhB and the surface formation of Poly(AMPS-co-DVB). With increasing of molar ratio of AMPS/DVB, the adsorption efficiency increased gradually. In the adsorption process, both physical and chemical mechanism is presence to adsorb RhB. The maximum adsorption capacity could get 407.9mg/g within 2h at room temperature.


      PubDate: 2016-05-10T18:54:30Z
       
  • Modification of Eucalyptus and Spruce organosolv lignins with fatty acids
           to use as filler in PLA
    • Abstract: Publication date: Available online 9 May 2016
      Source:Reactive and Functional Polymers
      Author(s): Oihana Gordobil, Itziar Egüés, Jalel Labidi
      Spruce (softwood) and Eucalyptus (hardwood) woods were used as raw material for lignin extraction by organosolv process. Chemical, structural and thermal characterizations of the extracted lignin samples have been performed using HPLC, GPC, FT-IR, 31P NMR, 13C NMR, DSC and TGA. Both lignins showed high purity, being Spruce lignin (OS) which presented the highest Klason lignin content (93%) and lowest sugar (0.5%) and sulphur (0.04%) content. Extracted lignin samples were chemically modified with dodecanoyl chloride fatty acid, in order to modify its thermal properties as glass transition temperature (Tg). The noticeable increase in the molecular weight and sharp decrease of Tg can be appreciated. Esterified lignins were used as filler in poly(lactic acid) (PLA) films elaborated by solvent casting in different concentrations (1, 5, 10, 25 and 50%). Mechanical, thermal and water barrier properties of prepared films were investigated. The results showed that the addition of both modified lignins contributed to greater ductility and lower stiffness, providing plasticity to PLA.


      PubDate: 2016-05-10T18:54:30Z
       
  • Comparison between two different click strategies to synthesize
           fluorescent nanogels for therapeutic applications
    • Abstract: Publication date: Available online 10 May 2016
      Source:Reactive and Functional Polymers
      Author(s): Emanuele Mauri, Irene Moroni, Luca Magagnin, Maurizio Masi, Alessandro Sacchetti, Filippo Rossi
      The development of nanogels as nanoscale multifunctional polymer-based matrices for controlled drug and gene delivery purposes has been the subject of intense research during the last decades. Their use in biomedical field is related to the effect of their size on the interactions with living cells: only within a defined range nanoparticles could be subjected to active or passive cellular uptake. In this work we propose two methods to synthetize Rhodamine modified nanogels in order to produce nanostructures that could be traced during the cellular interactions and internalization and suitable as carrier for drugs or genes. We compared the obtained sizes and charges of both nanogels, underlining which one could be more useful for biological and therapeutic applications referring to the morphological and physico-chemical properties requested in accordance with medical needs. We also tested their cytocompatibility and their characteristic behavior as drug delivery vehicles.
      Graphical abstract image

      PubDate: 2016-05-10T18:54:30Z
       
  • A new route toward imidazoline-functionalized porous polymeric materials
           from corresponding polystyrene-polylactide diblock copolymers
    • Abstract: Publication date: Available online 10 May 2016
      Source:Reactive and Functional Polymers
      Author(s): Joaquin Arredondo, Luis Ernesto Elizalde, Benjamin Le Droumaguet, Daniel Grande
      Novel imidazoline-functionalized diblock copolymers based on polystyrene (PS) and poly(D,L-lactide) (PLA) were synthesized as precursors to corresponding functional PS-based porous materials through a three-step sequential methodology starting from an asymmetric heterobifunctional initiator. α-Hydroxyl poly(4-cyanostyrene-co-styrene) random copolymers were first obtained via an atom transfer free-radical polymerization (ATRP) procedure by varying the amount of 4-cyanostyrene in the comonomer feed. Cyano groups were then transformed into corresponding imidazoline rings. Subsequently, the microwave-assisted ring-opening polymerization (ROP) of d,l-lactide from the imidazoline-functionalized PS-based macroinitiators allowed for the generation of semi-degradable diblock copolymers with different PLA volume fractions so as to develop microphase-separated morphologies. The precursors and resulting copolymers were analyzed by 1H, 13C NMR, and FT-IR spectroscopy. Upon induced shear-flow via channel-die processing, oriented materials constituted of PLA nanodomains in a polystyrene-based continuous matrix were formed. Hydrolysis in alkaline conditions of the PLA sacrificial block yielded imidazoline-functionalized porous PS-based matrices. The resulting porous frameworks were analyzed by scanning electron microscopy (SEM) and nitrogen sorption porosimetry.


      PubDate: 2016-05-10T18:54:30Z
       
  • Fabrication of self-cross-linking fluorinated polyacrylate latex particles
           with core-shell structure and film properties
    • Abstract: Publication date: Available online 26 April 2016
      Source:Reactive and Functional Polymers
      Author(s): Ting Lü, Dongming Qi, Dong Zhang, Qian Liu, Hongting Zhao
      A series of self-cross-linking fluorinated polyacrylate latex particles with core-shell structure were successfully prepared by one-step miniemulsion polymerization of methyl methacrylate (MMA), butyl acrylate (BA), dodecafluoroheptyl methacrylate (DFMA), and γ-methacryloxypropyl triisopropoxidesilane (MPS). The core-shell structure of the latex particles was confirmed and the latex films were characterized. Results showed that the latex films not only showed enhanced thermostability but also exhibited good hydrophobic property with the incorporation of a small amount of MPS (below 5wt% of monomers). This core-shell fluorine/silicone-containing polyacrylate latex could potentially be used for developing advanced multifunctional protective coatings such as antiwetting, anti-icing, antifogging, and anticorrosion.


      PubDate: 2016-04-29T18:48:56Z
       
  • Multifunctionality of self-assembled nanogels of curcumin-hyaluronic acid
           conjugates on inhibiting amyloid β-protein fibrillation and
           cytotoxicity
    • Abstract: Publication date: Available online 27 April 2016
      Source:Reactive and Functional Polymers
      Author(s): Zhiqiang Jiang, Xiaoyan Dong, Hu Liu, Yongjian Wang, Lei Zhang, Yan Sun
      Aggregation of amyloid β-protein (Aβ) is a major pathological hallmark of Alzheimer's disease. Curcumin has been recognized as an inhibitor of Aβ aggregation, but its low water solubility and bioavailability limits its clinical applications. In this work, we conjugated curcumin to hyaluronic acid and drastically improved its solubility and stability. We found that the conjugates self-assembled into nanosized hydrogels that inhibited Aβ fibrillogenesis and mitigated the amyloid cytotoxicity more efficiently than free curcumin. More importantly, we found that there was an optimal curcumin substitution degree, at which the hydrogel exhibited the strongest inhibitory effect. Based on these findings, a mechanistic model was proposed. It suggested that besides the inhibitory effect of the conjugated curcumin, HA provided three synergistic functions. The first is that curcumin encapsulation into nanogels protected cells from the toxicity of free curcumin. The second was an isolation effect of the hydrogel network, which hindered the interactions between Aβ molecules. The third was the counteraction of the hydrophobic binding between Aβ and the conjugated curcumin against the electrostatic repulsion between the like-charged Aβ and HA. The two opposite forces could stretch the conformation of Aβ monomers, slowing down the aggregation and/or leading to off-pathway aggregations. This work offered new insights into the development of more potent nanoparticles for inhibiting Aβ fibrillogenesis and cytotoxicity.


      PubDate: 2016-04-29T18:48:56Z
       
  • Photoinduced detachment of cells adhered on 2-methacryloyloxyethyl
           phosphorylcholine polymer with cell binding molecule through
           photocleavable linkage
    • Abstract: Publication date: Available online 27 April 2016
      Source:Reactive and Functional Polymers
      Author(s): Batzaya Byambaa, Tomohiro Konno, Kazuhiko Ishihara
      We prepared a novel substrate that its surface properties, e.g., cell adhesivity can be precisely and independently controlled by photoirradiation. The control of surface properties was achieved through an amphiphilic photoresponsive polymer; poly(2-methacryloyloxyethyl phosphorylcholine (MPC)-co-n-butyl methacrylate (BMA)-co-4-[4-(1-hydroxyethyl)-2-methoxy-5-nitrophenoxy]butyric acid (PL)) (PMB-PL). The PL unit can be cleaved into two parts via the external photoirradiation, which allows a successful detachment of cells adhered on the material surface. We immobilized epidermal growth factor (EGF) onto PMB-PL surface through a condensation reaction with carbonyl group on PL units to increase binding ability to specific cells. The EGF receptor overexpressed human skin epidermoid carcinoma epithelial cells (A431 cells) were used as a model cell line. The number of adhered cells was significantly increased on the EGF conjugated surface comparing to bare PMB-PL surface, although there was no cell attachment observed on poly(MPC-co-BMA) surface. The surface immobilized EGF also helped to enlarge the adherent areas of cell morphologies on surface, in contrast with an observation of round-shaped morphologies of adhered cells on bare PMB-PL surface. A simple photoirradiation procedure caused a successful detachment of adherent cells from the surface both PMB-PLs without and with immobilized EGF. The detached cells by photoirradiation were exhibited a very high cell viability and active proliferation rate as well as the non-irradiated control cells. Here, we demonstrated an easy way to immobilize biologically active molecules onto PMB-PL surfaces. We observed that immobilized bioactive molecules clearly affect the cellular morphologies and increase the efficiency of photoinduced detachment from the surface. We believe that the PMB-PL substrate can be a promising cell-collection platform for cell-based analysis through immobilized bioactive molecules, e.g., EGF that controls cellular behavior on 2D surface.


      PubDate: 2016-04-29T18:48:56Z
       
  • Ring expansion-controlled radical polymerization: Synthesis of cyclic
           polymers and ring component quantification based on SEC–MALS
           analysis
    • Abstract: Publication date: Available online 20 April 2016
      Source:Reactive and Functional Polymers
      Author(s): Atsushi Narumi, Shuhei Hasegawa, Ryo Yanagisawa, Miho Tomiyama, Masatsugu Yamada, Wolfgang H. Binder, Moriya Kikuchi, Seigou Kawaguchi
      We report a ring expansion vinyl polymerization producing cyclic polymers using a tetra(oxyethylene) (TOE)-tethered cyclic initiator for the nitroxide-mediated controlled radical polymerization (NMP). Styrene (St) was polymerized with the cyclic NMP initiator 1 in the bulk to produce polymer 2. Structural analyses of 2 were performed by a size exclusion chromatograph equipped with a multiangle laser light scattering (SEC–MALS) detector, focusing on the relationships between the z-averaged root-mean-square radii of gyration (〈S 2〉z 1/2) versus the molecular weights. The results proved that 2 would consist of ring components as a result of the ring expansion polymerizations and radical ring crossover reactions together with ring-opened linear components, in which the amount of ring components increased with the increasing molecular weights. The data also enabled the quantification that approximately 13–40wt% of the final polymer 2 could be identified as the ring species in the M w range of 1×105–5×105 gmol−1.


      PubDate: 2016-04-24T18:47:28Z
       
  • DMAP-based flexible polymer networks formed via Heck coupling as efficient
           heterogeneous organocatalysts
    • Abstract: Publication date: Available online 22 April 2016
      Source:Reactive and Functional Polymers
      Author(s): Wei Xu, Wu Xia, Yukun Guan, Yiming Wang, Cuifen Lu, Guichun Yang, Junqi Nie, Zuxing Chen
      Two DMAP-based flexible polymer networks TPB-DMAP and TPA-DMAP have been successfully synthesized via palladium catalyzed Heck cross-coupling. The structures of these polymers were confirmed by solid state 13C CP/MAS and Fourier transform infrared spectroscopy (FTIR). Although both polymers have negligible surface areas, they exhibit excellent catalytic efficiency for the acylation of 1-phenylethanol with acetic anhydride due to their good swelling capacities. Utilized as a typical catalyst, the polymer TPA-DMAP shows high activities for acylation of a variety of alcohols to the corresponding esters. Moreover, the catalyst can be recycled at least ten times without obvious loss of catalytic activity.


      PubDate: 2016-04-24T18:47:28Z
       
 
 
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